Multiple print engine system with selectively distributed ripped pages

ABSTRACT

A multiple print engine configuration allows a plurality of workstations to create individual print jobs and then transfer them to a distributing processor. The distributing processor is operable to spool the jobs in a print spooler and then perform a software RIP on the print jobs. The RIP process divides the jobs into multiple individual jobs which are stored in the page buffer. An image task manager in conjunction with an engine manager are then operable to selectively distribute the pages to multiple print engines. They are distributed in such a manner that they are placed in the output bins in the order that the pages were received in the print jobs.

CROSS REFERENCE TO RELATED APPLICATIONS

[0001] The present application is a Continuation of U.S. patentapplication Ser. No. 08/511,641, filed Aug. 7, 1995 and entitled“MULTIPLE PRINT ENGINE SYSTEM WITH SELECTIVELY DISTRIBUTED RIPPEDPAGES,” which is related to U.S. Pat. No. 5,596,416, and entitled“Multiple Printer Module Electrophotographic Printing Device.”

TECHNICAL FIELD OF THE INVENTION

[0002] The present invention pertains in general to electrophotographicprinters and, more particularly, to a plurality of print enginesarranged in parallel to process print jobs in a parallel manner.

BACKGROUND OF THE INVENTION

[0003] Electrophotographic print engines have been utilized with bothprinters and copiers. In a printer, the print engine is typicallyinterfaced with a computer to select and organize fonts or bit map theimages. In a copier application, the print engine is interfaced with aninput device that scans the image onto the photoconductor drum of theprint engine. However, a CCD device could also be utilized in thisapplication in the form of a CCD scanner. In either of the applications,a conventional print engine for a monochrome process would typicallyfeed a single sheet of paper and pass it by the photoconductor drum foran image transfer process and then pass it to a fuser. Thereafter, thecompleted sheet will be output. Multiple copy print jobs willsequentially feed the paper in a serial manner. The speed of the printeris a function of the speed at which the image can be created, the speedat which the image can be transferred to the paper and the speed of thefuser. As increased output is required, the speed of each of theseelements must be increased.

[0004] In a monochrome process, only one transfer operation is required.However, in a multipass color process, multiple images must besuperimposed on one another on the sheet of paper in a direct transfersystem, thus requiring multiple passes of the paper or image carrierthrough the print engine. In a double transfer system, the image isdisposed on an intermediate drum and then the composite imagetransferred to the paper or image carrier. In a multiple print job on adirect transfer system, this requires each sheet of paper to be printedin a serial manner by passing it through the print engine. For eitherthe monochrome process or the color process, a conventional serial feedprint engine has the output thereof defined by the speed of the inputdevice and the speed of the print engine itself.

[0005] One technique that has been utilized to increase throughput is atandem print engine. In a tandem print engine, multiple colors can bedisposed on the sheet of paper or the image carrier at differentstations that are disposed in serial configuration. In this manner, thespeed is the same for one, two, three or four color printing.

SUMMARY OF THE INVENTION

[0006] The present invention disclosed and claimed herein comprises amultiple print engine system. The system includes at least oneworkstation for generating one or more print jobs having a plurality ofcopies associated with each print job. A RIP engines is operable toreceive the print job and parse it into separate pages in associationwith the print job. These are then disposed in a page buffer. Aplurality of printers are then provided which are each accessible inparallel. A processor is operable to select pages from the page bufferand output them to select ones of the printers in a predetermined order.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] For a more complete understanding of the present invention andthe advantages thereof, reference is now made to the followingdescription taken in conjunction with the accompanying Drawings inwhich:

[0008]FIG. 1 illustrates an overall block diagram of the presentinvention;

[0009]FIG. 2 illustrates a more detailed block diagram of the presentinvention;

[0010]FIGS. 3a, 3 b and 3 c illustrate three general processingconfigurations;

[0011]FIG. 4 illustrates a cutaway side view of a three module multipleprint engine operated in accordance with the present invention;

[0012]FIG. 5 illustrates a flowchart illustrating the parsing operation;

[0013]FIG. 6 illustrates a flowchart for the duplex operation for a faceup output; and

[0014]FIG. 7 illustrates a flowchart for the duplex operation for a facedown output.

DETAILED DESCRIPTION OF THE INVENTION

[0015] Referring now to FIG. 1, there is illustrated a block diagram ofthe overall operation of the present invention. A plurality ofworkstations 10 are provided, which workstations 10 comprise generalpersonal computers or other terminals that allow a user to create printjobs. Each of the workstations is networked through a network interface12, which is a conventional type of general network interface such as anEthernet® network interface. This allows each workstation 10 to send itsprint job to a central processor 14, which processor is operable toprocess the print jobs in accordance with the system of the presentinvention and distribute these print jobs to multiple print engines 16.As will be described hereinbelow, the processor 14 is operable todisassemble the print job, parse the print job into different pages anddistribute the parsed pages in a predetermined manner in accordance withthe present invention. It should be understood that a print job,although initiated as a series of pages, is sent as a single job to aprinter. Typically, printers receive the print job in a conventionalmanner, which is a string of digits and the printers determine whetherthe codes are for an end of page command, etc. However, most printoperations within a given workstation 10 are designed such that theprint job is to be sent to a single printer and, therefore, the codesare all “bundled” in a common string or job. As will be describedhereinbelow, in order for the pages to be parsed, it is important tofirst determine what the beginning and the end of a print job is, thendetermine what printer to send that distinct and separate page to, inaccordance with the system of the present invention.

[0016] Referring now to FIG. 2, there is illustrated a more detailedblock diagram of the operation of the processor and the parsingoperation for distributing the parsed pages to the various print engines16. The job is received in a serial manner, and is “spooled” in a printspooler 20. This is then passed to a software RIP engine 22 which isoperable to essentially decode the print string that is received fromthe print spooler 20. This effectively divides each print job intopages. These pages are then stored in page buffers 24. Each page in thepage buffer essentially constitutes a single print job, such that anyprint job received from the workstations 10 will then be parsed into amultiple print job file. For example, if a thirty page document were tobe sent, this would be sent as a single print job, which would beencoded as such. The software RIP engine 22 is then operable to dividethis into thirty separate print jobs.

[0017] Once the pages are stored in the page buffer 24, then the pagesare sent to an image task manager 26 to determine how to organize thepages. This operates in conjunction with an engine manager 28 todetermine which of the print engines 16 the job is to be passed to. Inorder to effectively increase the throughput from the engine manager 28,there are provided interface circuits 32 which are referred to asPeripheral Connect Interface (PCI) adaptors. Each print engine 16 has aPCI 32 associated therewith. Therefore, the engine manager 28 interfaceswith the PCIs 32 through a parallel bus 36, such that data can betransferred thereto at a fairly high data rate, which is the bustransfer data rate of the processor 14. The PCIs 32 therefore provide anincreased rate of transfer to the print engine 16. The print engines 16then place their output into a separate output bin 40 for each of theprint engines 16.

[0018] As will be described hereinbelow, the image task manager 26 isoperable to arrange the copies such that they can be placed in theoutput bins 40 in a predetermined order. For example, if there were twoprint engines, each with a 100 sheet paper supply and four print jobs of50 copies each were to be sent to the printers and the workstation 10,the system of the present invention would parse these print jobs suchthat the first two print jobs went to the first print engine and thesecond two print jobs went to the second print engine. If,alternatively, the two print engines with the one hundred sheet papersupplies handled two print jobs, one at a 150 sheets and one at 50sheets, then the first print engine would receive the first 100 sheetsfrom the first print job, the second print engine would receive thefirst 50 sheets of the first print job and the second 50 sheets of thesecond print job. However, they would be sent to the printer in such amanner that when the paper output trays were unloaded and stackedtogether, the jobs would be arranged in the appropriate manner.Therefore, even though there are multiple printers, to the user theyappear as a virtual single printer. All decision making is made in theprocessor 14.

[0019] Referring now to FIGS. 3a-3 c, there are illustrated the variousconfigurations illustrating the transfer of data between an input and aprint engine. In FIG. 3a, there is illustrated a general diagram of asoftware RIP processor 42, which is operable to generate the datanecessary to transfer to a print engine 46. However, this is effectedover a conventional parallel port 48. In this configuration, thesoftware RIP processor 42 is relatively fast, whereas the print engine46 is relatively slow. Of the time to print, three percent of that timeis occupied by the operation of print engine 46, seventy percent isoccupied by the software RIP processor 42 and twenty-seven percent isoccupied by transferring the data from the processor 42 to the printengine 46. Therefore, the parallel port 48 becomes a key factor in theprinting time. In FIG. 3b, software RIP processor 42 is connected to theprint engine 16 via a PCI 50. In this configuration, ninety-five percentof the print time is occupied by the software RIP processor 42, threepercent by the print engine 16 and five percent by the PCI 50.Therefore, by reducing the transfer time from the processor 42 to theprint engine 16, an increase in speed has been seen. In FIG. 3c, thereis illustrated a fairly conventional system wherein a processor 52 isprovided, which can be a conventional PC for assembling the print job ina conventional manner and transferring it via a parallel port 54 to anengine 58, which is a conventional print engine having an internal RIP60 associated with a marking engine 62. The processor 52 is relativelyfast, and it occupies virtually no time. Seventeen percent of the printtime is taken passing the data to the RIP 60 through the parallel port54, whereas eighty percent of the print time is occupied with the RIP 60and only three percent by the marking engine 62.

[0020] Referring now to FIG. 4, there is illustrated a cutaway side viewof a three print engine module parallel printer which includes threeprint engines 136, 138 and 40, all stacked one on top of the other. Eachof the engines 136-140 is a multi-pass engine and includes a transferdrum 142 and a photoconductor drum 144. The photoconductor drum 144rotates in a counterclockwise direction and is pressed against thetransfer drum 142 to form a nip 146 therebetween. The photoconductordrum 144 is operable to have the surface thereof charged with a corona148 and then an imaging device 150 is provided for generating a latentimage on the charged surface of the photoconductor drum 144. Theundeveloped latent image is then passed by four developing stations,three color developing stations, 152, 154 and 156 for the colors yellow,magenta and cyan, and a black and white developing station 158. Thecolor developing stations 152, 154 and 156 each have a respective tonercartridge 160, 162 and 164 associated therewith. The black and whitedeveloping station 158 has a black and white toner cartridge 166associated therewith. Although not described hereinbelow, each of thedeveloping stations 152-168 and toner cartridges 160-166 can be removedas individual modules for maintenance thereof.

[0021] During the print operation, the photoconductor drum 144 isrotated and the surface thereof charged by the corona 148. Anundeveloped latent image is then formed on the surface of thephotoconductor drum 144 and then passed under the developing stations150-158. In a multi-pass operation, the latent image is generated andonly one color at a time utilized in the developing process for thelatent image. This latent image is then passed through the nip 146 andtransferred to an image carrier, such as paper, which is disposed on thesurface of the transfer drum 142. Thereafter, the surface of the drum144 is passed under a cleaning station 168, which is operable to removeany excess toner particles which were not passed over to the transferdrum 142 during the transfer operation and also discharges the surfaceof the drum 144. The system then begins generation of another latentimage, either for a different color on the same sheet of paper or thefirst color on a different sheet of paper.

[0022] In the color operation, multiple passes must be made such thatthe image carrier, i.e., paper, remains on the surface of the transferdrum 142 for the multiple passes. In the first pass, the first latentimage is transferred to the surface of the transfer image carrier andthen the image carrier maintained on the transfer drum 142. The nextlatent image of the next color is superimposed on the first latentimage, it being noted that the registration is important. Thisregistration is provided by the mechanical alignment of the variousdrums, drive mechanisms, etc. Thereafter, the third color latent imageis disposed on the image carrier followed by the fourth color latentimage.

[0023] After the last color latent image is disposed on the imagecarrier in the color process, a picker mechanism 172 comes down on thesurface of the transfer drum 142 in order to lift up the edge of theimage carrier or paper. This is then fed to a fuser mechanism 174.

[0024] The image carrier is typically comprised of a predeterminedweight paper. The transfer drum 142 utilizes electrostatic gripping forthe purpose of adhering the paper to the surface of the transfer drum142 for multiple passes. This therefore utilizes some type of chargingmechanism for charging the surface of the drum 142 at an attachmentpoint 176 where the paper is fed onto the surface of the transfer drum142. The transfer drum 142 is, in the preferred embodiment, manufacturedfrom a controlled resistivity type material that is disposed over analuminum support layer which is a hollow cylindrical member. A voltagesupply is provided that provides a uniform application of voltage fromthe voltage supply to the underside of the resilient layer that isdisposed over the surface of the aluminum support member. This resilientlayer is fabricated from a carbon filled elastomer or material such asbutadaiene acrylonitorile, which has a thickness of approximately 3 mm.Overlying this resilient layer is a controlled resistivity layer whichis composed of a thin dielectric layer of material at a thickness ofbetween 50 and 100 microns. This controlled resistivity layer has anon-linear relationship between the discharge (or relaxation) pointtying and the applied voltage such that, as the voltage increases, thedischarge time changes as a function thereof. The paper is then disposedover the surface of the drum. The construction of this drum is describedin U.S. patent application Ser. No. 08/141,273, filed Dec. 6, 1993, andentitled, “Buried Electrode Drum for an Electrophotographic Print Enginewith a Controlled Resistivity Layer” (Atty. Dkt. No. TRSY-21,880), whichis a continuation-in-part of U.S. patent application Ser. No.07/954,786, filed Sep. 30, 1992, and entitled, “Buried Electrode Drumfor an Electrophotographic Print Engine” (Atty. Dkt. No. TRSY-21,072),which U.S. patent application Ser. No. 07/954,786, is incorporatedherein by reference.

[0025] The paper is retrieved from one of two paper supply bins 178 or180. The paper supply bin 178 contains one type of paper, typically8½″×11″ paper, and the paper bin 180 contains another type of paper,typically 8½″×14″ paper. The paper bin 178 has the paper stored thereinselected by a first gripping roller 182, which is then fed along a paperpath 180 into a nip 182 between two rollers and then to a nip 184between two rollers. This is then fed to a paper path 186 to feed into anip 188 between two rollers. The paper in the nip 188 is then fed into anip formed between two precurl rollers 190 and 192, which have differentdurometers to cause the paper to have a curl bias applied thereto in thedirection of the curvature of rotation of the transfer drum 142. Theoperation of the pre-curl rollers is described in detail in U.S. Pat.No. 5,398,107, issued Mar. 14, 1995, and entitled, “Apparatus forBiasing the Curvature of an Image Carrier on a Transfer Drum” (Atty.Dkt. No. TRSY-22,574). The paper from the bin 180 is extracted by agripping roller 189 and pushed along a paper path 191 to the nip 188 andtherefrom to the pre-curl rollers 190 and 192.

[0026] The paper is fed from the nip between the two pre-curl rollers190 and 192 at the attachment point 176. At the attachment point 176, anattachment electrode roller 194 is provided which is operable to operateon a cam mechanism (not shown) to urge the roller 194 against thesurface of the drum 142 to form the attachment nip 176. This is doneduring the initial attachment of the paper to the drum 142. Typically,this attachment electrode roller 194 is connected to ground. The surfaceof the drum 142 is charged to a positive voltage of between 800-1,000volts. The voltage is disposed on the surface of the drum 142 by apositive electrode roller 196 that contacts the surface of the drum 142at a point proximate to the photoconductor drum 144. Since the electrode194 is grounded, the voltage will decrease along the surface thereofuntil a lower voltage is present at the attachment point 176. When thepaper reaches the transfer nip 146, the portion of the surface of thephotoconductor drum 144 in the nip 146 has a potential thereof reducedto ground such that the charged particles will be attracted from thesurface of the photoconductor drum 144 to the surface of the paper onthe drum 142.

[0027] For a multiple pass operation, the attachment electrode 176 willbe pulled outward from the drum and the paper allowed to remain on thedrum and go through the transfer nip 146 for another pass. When thefinal pass has been achieved at the transfer nip 146, the picker 172 isswung down onto the surface of the drum 142 to direct the paper on thesurface of the drum 142 to the fuser 174. A discharge electrode 198 isthen swung down into contact with the drum 142 to provide a dischargeoperation before the surface of the drum enters the nip 176 for the nextpaper attachment process.

[0028] When the paper is fed into the fuser 174, it is passed into a nipbetween two rollers 200 and 202, both of which have differentdurometers. Typically, there is one roller that is formed from ametallic material and one roller that is formed of a soft material. Therollers are oriented with the roller 200 having the smaller durometer,such that a reverse bias curl will be applied to the paper that is theopposite direction of the curvature of the drum 142. This will removethe curvature added to the paper. One of the rollers 200 is heated suchthat the transferred image is “fused”. The paper is then fed into apaper path 204 by a pair of rollers 206. The paper path 204 is fed a setof output rollers 208, which feed bins 210, 212 and 214 for each of theprinters 136, 138 and 140. Again, these are conventional print engines,although the speeds of the print engines may be different.

[0029] Referring now to FIG. 5, there is illustrated a flowchartdepicting the operation of the present invention. For this description,the following terms are defined:

[0030] N=number of pages in a single document

[0031] M=copies

[0032] E=number of engines

[0033] P=number of pages

[0034] I=the engine number.

[0035] The flowchart is initiated at a start block 230 and then proceedsto a decision block 232. A decision block 232 multiples the number ofpages N by the number of copies M and determines whether this number ifgreater than or equal to the number of engines. If not, then the programflows along a “N” path to a function block 234 to utilize only a singleengine for the print job. However, if the number is greater than thenumber of engines, then the program proceeds along the “Y” path to adecision block 236 to determine the number of copies M is greater thanthe number of engines E. If not, the program flows along a path “N” to adecision block 238 to determine if the number of pages in a singledocument “N” is greater than or equal to the number of engines. If not,the program will flow along a “N” path to a function block 240 toutilize the only M engines with the I^(th) copy in the I^(th) engine.Therefore, if there are ten engines and only five copies then the fifthcopy of a job will be in this ith engine. If, however, the number ofcopies in a single document is greater than the number of engines, thenthe program will flow along a “Y” path to a function block 242 whereinthe copies will be distributed in accordance with the equation:$\begin{matrix}{P = \frac{N \times M}{E}} & (1)\end{matrix}$

[0036] If it was determined in the decision block 236 that the number ofcopies M was greater than the number of engines with the number ofcopies times the number of pages in a single document also being greaterthan the number of engines, then the program flows along the “Y” pathfrom decision block 236 to a decision block 244 to distribute copies.These are distributed in accordance with the algorithms illustrated inFIG. 5 with respect to four of the engines E₁, E₂, E₃ and E₄. E₁, E₂ andE₃ are also associated with function blocks 246, 248 and 250, eachoperating in accordance with the above equation, one associated withfunction block 242. However, E₄ will flow to a function block 256wherein the distribution will be as follows:

P ₄ =N×M−(P ₁)+P ₂+2P ₃)  (2)

[0037] Referring now to FIG. 6, there is illustrated a flowchartdepicting the operation for a duplex print job. In the flowchart of FIG.6, a face up output is considered which is initiated at a block 260. Thefunction block then flows to a decision block 262 to determine if thevalue of N is even. If so, the program flows to a function block 264 toprint the jobs −2, −4 . . . , 2. The program then flows to a decisionblock 266, which determines whether the value of N is odd. However, if Nwas odd at decision block 266, the program would flow along the “N” pathto the output of the decision block 266 and then to a function block 268to print the N+1 copies and blank copies and then print the N−1, N−3, .. . 1 pages. The flowchart would then flow to a function block 270. Itis noted that if N is even at decision block 266, the program would flowto the function block 270. Function block 270 is a function blockwherein a user annually turns the output stack 180° without flipping thestack and then puts it back in the drawer of the printer from which itcame. The program then flows to a decision block 74 to determine if thevalue of N is even, and if so, to the function block 270 along the “Y”path to print the pages 1, 3, 5, . . . −1, and then to a decision block278 to determine if the value of N is odd. The program at this pointwill flow along the “N” path to a N block 280. However, if the value ofN is determined to be odd at decision block 274, the program will flowthrough the output of decision block 278 and to the input of a functionblock 282 which will print the pages 1, 3, 5, . . . N.

[0038] Referring now to FIG. 7, there is illustrated a flowchartdepicting the duplex operation with a face down output, which isinitiated at a block 284 and then proceeds to a decision block 286 todetermine if the value of N is even. If so, the program then flows to afunction block 288 along the “Y” path to print the pages 2, 4, 6, . . .N. If it was determined that the value of N is odd, the program wouldflow along an “N” path to a function block 290 to print the pages 2, 4,6, . . . −1. The program 288 would flow to a decision block 294, whichdetermines if N is odd and, if not, flows along a “N” path to the outputof function block 290, the output of a decision block 294 is input tofunction block 290. The output of function block 290 flows through afunction block 296, as well as the output along the “N” path of decisionblock 294. Decision block 296 indicates the manual operation wherein theuser flips the output stack without turning it 180° and then inputs itback into the drawer of the printer from which it was obtained. Theprogram will then flow to a decision block 298 to determine if the valueof N is even. If so, the program flows along a “Y” path to a functionblock 300 and the pages 1, 3, 5, . . . −1 and then to the input of adecision block 302. If the value of N is odd, the program flows alongthe “N” path from decision block 298 to the output of decision block 308and to a function block 306 to print the pages 1, 3, 5, . . . N. Theoutput of the decision block 302 along the “Y” path also flows to thefunction block 306 when N is even, and the flowchart flows along the “N”path to an “END” block 310, this being the path from the function block306.

[0039] In summary, there has been provided a multiple print engineconfiguration wherein multiple jobs can be configured as a single printjob, transferred to a central distribution processor which parses theprint jobs into single pages and then determines how to pass them tomultiple print engines such that, when output therefrom are such thatwhen a user stacks them up from the output bin the order in which theprinters are arranged, or in any type of predetermined order, the pageswill be in a sequential manner as the print jobs were received.

[0040] Although the preferred embodiment has been described in detail,it should be understood that various changes, substitutions andalterations can be made therein without departing from the spirit andscope of the invention as defined by the appended claims.

What is claimed is:
 1. A multiple print engine system, comprising: atleast one work station for generating a print job having a plurality ofpages associated therewith; a RIP engine for receiving said print jobfrom said workstation and RIPing said print job to provide a RIPed printjob; a parsing device operating in conjunction with said RIP engine forparsing the RIPed print job to defined pages, the pages associated withthe print job; a page buffer for storing the RIPed pages in associationwith the print job that they were generated in; a plurality of printersfor receiving one of the RIPed pages and printing the received RIPedpages and outputting them in an associated output bin; and a processorfor selectively distributing after RIPing all or a portion of said RIPedprint job by outputting select RIPed pages from said RIPed print jobstored in said page buffer for printing by select ones of said printersin a predetermined order for output as sheets in the associated outputbin.
 2. The multiple print engine system of claim 1, wherein there are aplurality of work stations provided, each for generating one or moreprint jobs for input to said RIP engine and a spooler disposed prior tosaid RIP engine for receiving said print jobs in parallel and outputtingsaid spooled print jobs serially to said RIP engine.
 3. The multipleprint engine system of claim 1, wherein said predetermined order is theorder of the copies in said print job, such that pages output from onesof said print engines, which print engines are arranged in apredetermined order, are in the order that they existed in the print jobwhen the sheets are stacked from the print engine order.
 4. The multipleprint engine of claim 1, wherein said page buffer comprises a singlepage buffer for storing all of said RIPed pages.
 5. The multiple printengine of claim 1, wherein the defined pages in each of said RIPed printjob comprise a bit-mapped image of each of said pages in the originalprint job.
 6. The multiple print engine of claim 1, wherein said RIPengine comprises a single RIP engine.
 7. The multiple print engine ofclaim 6, wherein said RIP engine operates in a central processing unitand is a software-based RIP engine.
 8. The multiple print engine ofclaim 1, and further comprising a plurality of communication links, eachof said communication links disposed between said processor and one ofsaid plurality of printers, such that a separate communication path isprovided from said process to each of said plurality of printers fortransmitting said RIPed pages thereacross.
 9. A multiple print enginesystem, comprising: at least a single work station for generating aprint job having a plurality of pages associated therewith anddesignated for a single print engine; a RIP engine for receiving saidprint job from said workstation and RIPing said print job to provide aRIPed print job; a parsing device operating in conjunction with said RIPengine for parsing the RIPed print job to define pages, the pagesassociated with the print job; a page buffer for storing RIPed pages forthe received print job; a plurality of printers for receiving one of theRIPed pages and printing the received RIPed pages and outputting them inan associated output bin; and a distributor for selectively distributingafter RIPing to a select one or ones of said printers all or a portionof said RIPed print job by outputting select RIPed pages from said RIPedprint job stored in said page buffer in an order determined by internalcriteria to said distributor and in accordance with aspects of saidprinters and independent of the designated printer information generatedby said at least one work station.
 10. The multiple print engine ofclaim 9, wherein the defined pages in each of said RIPed print jobcomprise a bit-mapped image of each of said pages in the original printjob.
 11. The multiple print engine of claim 9, and further comprising aplurality of communication links, each of said communication linksdisposed between said processor and one of said plurality of printers,such that a separate communication path is provided from said process toeach of said plurality of printers for transmitting said RIPed pagesthereacross.
 12. The multiple print engine of claim 9, wherein said RIPengine comprises a single RIP engine.
 13. The multiple print engine ofclaim 12, wherein said RIP engine operates in a central processing unitand is a software-based RIP engine.
 14. The multiple print engine ofclaim 9, wherein said page buffer comprises a single page buffer forstoring all of said RIPed pages.
 15. A method for printing to multipleprint engines, comprising the steps of: providing at least one workstation for generating a print job having a plurality of pagesassociated therewith; receiving the print job from the workstation andRIPing the print job with a RIP engine to provide a RIPed print job; inconjunction with the RIPing operation, parsing the RIPed print job todefined pages, the pages associated with the print job; storing in apage buffer the RIPed pages in association with the print job that theywere generated in; selectively distributing after RIPing all or aportion of the RIPed print job by outputting select RIPed pages fromsaid RIPed print job stored in said page buffer for printing by selectones of the printers in a predetermined order for output as sheets inthe associated output bin; and receiving one of the RIPed pages at theselect one of the printers and printing the received RIPed pages andoutputting them in an associated output bin.
 16. The method of claim 15,wherein there are a plurality of work stations provided, each forgenerating one or more print jobs for input to the RIP engine andfurther comprising the step of providing a spooler disposed prior to theRIP engine for receiving the print jobs in parallel and outputting thespooled print jobs serially to the RIP engine.
 17. The method of claim15, wherein the predetermined order is the order of the copies in theprint job, such that pages output from ones of the print engines, whichprint engines are arranged in a predetermined order, are in the orderthat they existed in the print job when the sheets are stacked from theprint engine order.
 18. The method of claim 15, wherein the page buffercomprises a single page buffer for storing all of the RIPed pages. 19.The method of claim 15, wherein the defined pages in each of the RIPedprint job comprise a bit-mapped image of each of the pages in theoriginal print job.
 20. The method of claim 15, wherein the RIP enginecomprises a single RIP engine.